Phycobiliproteins and their tandem dyes are important fluorochromes that are widely used as fluorescent labels in flow cytometry. The use of tandem dyes has expanded the capability for expanded multi-color analysis in flow cytometry by providing additional fluorochromes with distinct emission spectra using a single donor dye excited by one laser line.
When using many tandem dyes in multicolor combinations, difficulties in discriminating among fluorescence signals can occur. To date, the art has generally ascribed these “difficulties” as being due to dye instability. However, there have not been any definitive answers or suggestions for addressing these problems. Therefore, there remains a need in the art for compositions and methods for analysis which use unique combinations of phycobiliprotein-conjugated ligands. In particular, there remains a need in the art for phycobiliprotein containing tandem dye compositions that limit degradation over time encountered with compositions known in the art.